I don't think that's quite the right way to look at it. It's what is called a "value" brand, meaning that it's positioned to entice more price sens customers. This doesn't make it inferior, just aimed at a different customer segment.
Its like Dove soap vs Lever2000. Both are made by Unilever and both are fine soaps. But Dove is aimed at people willing to pay more because they perceive it to be better. But that doesn't necessarily mean it is better or costs more to produce.
GMC and Chevrolet, Tostitos and Santitos (tortilla chips), Budweiser and Natural Light; these are all examples of the phenomenon.
Pennzoil and Quaker State are the same way.